Artificial limb



-J. F. ROWLEY.

ARTIFICIAL LIMB.

APPLICATION FILED MAY 23, 192i- 7. 1,409,414 Patented Mar. 14, 1922. 9291. v v

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mmmumummy llmmmlmumn 3T lnveniap UNITED STATES JAMES F. ROWLEY, OF CHICAGO, ILLINOIS.

nn'nrrcmic LIMB.

Specification of Letters Patent.

Patented Mar. 14, 1922.

Application filed May 23, 1921. Serial No.{171,7182 H To all whom it may concern Be it known that I, JAMEsF. ROWLEY, a citizen of the United States of America, and a resident of Chicago, county of Cook and State of Illinois, have invented a new and useful Improvement in; Artificial Limbs, of which the following is a specification.

This invention relates to improvements in the knee structure of an artificial limb, and is a variation of the designs in applicants Patents No. 1,375,860, April 26, 1921, and No. 1,368,575, February 15, 1921. The subject matter common to all three cases pertains to bending and straightening the leg, that is, whenthe leg is raised from the ground in active walking, a bending action may be automatically imparted to it preliminary to straightening the leg as the foot nears its extreme forward position. In the two patents above mentioned, the bending action was somewhat more automatic than in the present case, wherein if desired the bending at-the knee may be merely such as is produced by a forward motion of the thigh, allowing the lower leg to remain substantially vertical until the leg supporting suspenders are" tensioned to draw the lower leg into axial alinement with the thigh. On the other'hand, withthe present construction, an automatic bending of the leg may be produced by a preliminary slight tensioning of the suspender. Therefore, with the present construction the leg may be lifted vertically without any forward motion of the thigh, and with or without bending, and it may also be swung forwardly with or without any bending of the leg taking place.

The objectsof the invention are accomplished by making a two-part back check, with provision for limited lost motion between the two parts of the back check, and a spring which is carried by one of theparts and cooperates with the remaining part through an intermediate fulcrum afforded by the lower end of the thigh section.

Figure 1 of the drawings shows in longitudinal vertical section an artificial limb constructed according to this invention.

Figure 2 is a detail in plan of the back check.

Figure 3 is a fragmentary detail of the back check taken on line 3.3 of Figure 2.

The construction illustrated comprises upper and lower leg sections pivoted together or articulated in some manner at the knee,

such as by the use of the customary'lmee bolt. The two-part back check leverfis in the form of a bell crank fulcrum on the knee bolt, the lower arm of the "lever being secured to the lower leg section, and the upper carrying at its forward end the usual pulleys for cooperating with the suspender loops. The two parts of the back check have a lost motion connection, the maximum motion permitted being that required for-the automatic flexing of the leg in walking, and

to allow for the desired tensioning of a spring under the control of the upper part of the lever when the leg is perpendicular to the ground; This spring at its lower end bears against the lower, part of the back check, and intermediate of its ends bears agalns't a fulcrum or pad atthe lower end of a the upper leg. 1 i

. With this construction, if the leg is vertical and carrying its normal weight,"the 7 spring may be tensioned by a slight upward motion of the shoulders drawing on the suspender, and then when the'leg is relieved of its load by lifting it from the ground, the spring imparts its energy to the lowerleg giving it a slight backward motion, the angle between the two parts of the leg then being increased by a forward motion of the thigh during the walking action.

The construction as illustrated comprises upper and lower legs 1 and 2 of usual construction and secured together by a knee bolt 3, around which the lower leg moves when changing its angular relation with the upper leg. The back check a is approxit ly a well-known design except that its two arms 5 and 6 are each fulcrumed on the knee bolt and connected together by pins or screws 7 on the part 6 and passing through apertures 8 at the rear end of the upper part 5 of the back check. The suspender loops 9 pass around pulleys 10 at the forward end of the upper part of the back check, and when these loops are tensioned with the leg in flexed position after the lost motion is taken up in the slot 8, the back check swings around its fulcrum as a unit,.swinging the lower leg section into axial alinement with the upper leg. The part5 of the back check has a pair in detail 6 of the back ch ck, and intermediate its ends, the spring bears against a pad 15 at the lower end of /the upper leg. I

\Vhen the leg; is perpendicular to the ground and carrying a load, if the suspend ers are tensionedi slightly, lost motion will be taken up between the two parts of the back check, and the spring 13, which is normally not under tension, is swung into engagement with the pad 15which is a fulcrum forthe spring, and therefore causes its lower end to bear with some pressure against the part 6 bending which takes place will be due to the lower leg remaining in substantially verti cal position. In active walking, the lower leg is automatically swung to coaxial alinement with the upper leg due to the involuntary tensioning of the suspenders.

. Although but one specific embodiment of this invention has been herein shown and described, it will be understood that numerous details of the construction shown may be altered or omitted without departing from the spirit of this invention as defined by the following claims.

I claim: 7 V

1, An artificial limb comprising pivotally connected upper and lower legs, a lever comprising two parts connected together for a limited relative angular motion, said lever being pivoted on one part of the leg and having one of its parts secured to the remaining part of the leg, a spring forproducing relative angular motion between the parts of the lever, and a suspender connected to a part of the lever whereby it may control the action of saidspring. v I

2. An artificial limb comprising pivotally connected upper and lower legs, a lever pivoted on one part of the leg and having one of its ends secured to the remaining part of the leg, a suspender connected. tosaid lever at its opposite end, said lever comprising twoparts connected together for limited relative angular motion, and a spring operativelyvconnected with the two parts of the lever.

3. An artificial limb comprising'pivotally connected upper and lower legs, a leverpivoted on one part of the leg'and having one of its ends secured to the remaining part of theleg, a suspender connected to said lever at its opposite end, said lever comprising two parts connected together for limited relative angular motion, and a leaf spring opera tively connected to the two parts of the lever and fulcrumed on the body of the leg.

4. An artificial limb comprising upper and lower legs pivotally connected, a back check lever formed of two parts each pivotally connected together for a limited lost motion,-

a leaf spring attached to the upper part of said lever and bearing at its lower end against the lower part of said lever, and a fulcrum bearing for'the spring on the upper leg. 7 r V H Signed at Chicago this20th day ofMay 1921. a e JAMES F. ROWLEY. I 

